Remove blue screen with blue object on it
Keying with a color background that is similar to the objects in the foreground is not a good idea...
Also, the background is not an uniform color, since the fabric has folds and wrinkles, so you will have to key out a large amount of different tones of blue, which will force you to use very aggressive settings for the key, which in turn will result in too much of the image being affected and degraded.
But since you voluntarily put your self on a bind and a challenge, you will have to work extra. KEY the background like you would normally, then you will need to create masks for the blue pail, and use those as core matte.

But you will notice that the key node has also taken away a lot of the blue component from the image, so the output has become useless.
You will then need to use the original image and associate the matte created by the key node and use it directly on the image with a set alpha node and an alpha convert node...

Then you will need additional masks to use as garbage matte to get rid of the dark areas (the folds on the fabric) to have a clean matte.

Then you'll realize that you need to bring back the shadow from the pail on the fabric... Getting the shadow information (and subtle gradations like reflections or transparency) would have been very easy to do with a proper flat background, but now you need to re-invent that portion of the image.
Then you'll realize that one of the other blue objects is also missing, so you need more masks...
This is way too much work for something that should have been very simple (and mostly automatic), extra work that could and should be avoided with proper preparation...

Now that you've seen the extra effort that it takes to do this, change the fabric to a color that is not present on the scene, stretch it so that it has no folds, and make a new picture and key it in a simpler and proper way... Key out that color so that you have a clear edge on the objects, enough information on the shadows and reflections and so on.
Even a black fabric would be easier to key (using a luminance key) than what what you have right now.